Improved microcirculation in patients with an acute ST-elevation myocardial infarction treated with the Impella LP2.5 percutaneous left ventricular assist device.

BACKGROUND

Circulatory support during percutaneous coronary intervention (PCI) in patients with ST-element elevation myocardial infarction (STEMI) aims at maintaining hemodynamic stability and organ perfusion. However, continuous flow pumps may interfere with the normal pulsatile circulation and the microcirculatory function. Sidestream dark field (SDF) imaging allows the visualization of microvascular structure and function of tissue and may provide information regarding the efficacy of the circulatory support.

METHODS

Sidestream dark field was used to study the sublingual microcirculation (MC) in six anterior STEMI patients treated with PCI; three patients received Impella LP2.5 percutaneous left ventricular support (Impella group) and three patients received no support (control group). MC was assessed at baseline, at 24, 48 and 72 h after PCI. Data were analyzed using a validated scoring method and the microvascular flow index (MFI) and perfused vessel density (PVD) were calculated. MC of three healthy controls was used as normalized standard.

RESULTS

Normal MC depending on both functional capillary density (PVD) and flow velocity or quality (MFI), as observed in healthy controls, was only achieved in the Impella group and paralleled improvement in LV function. Functional capillary density in the control and Impella groups were respectively equal and above the level of healthy controls. The quality of microcirculatory flow only in the Impella group reached values of healthy controls.

CONCLUSIONS

Microcirculation assessed by SDF improved in STEMI patients treated with the Impella LP2.5 to levels observed in healthy persons and remained suboptimal after 72 h in patients without support. Sublingual SDF to assess MC may serve as a monitor of effective myocardial recovery after PCI and optimization of organ perfusion.